2013). massMobile: towards a exible framework for large-scale participatory collaborations in live performances.massMobile is a client-server system for large audience participation in live performances using mobile devices. It allows for rapid development, deployment and iterative experimentation in participatory design, while minimising technical and logistical overhead. It was designed to flexibly adapt to a variety of participatory performance needs and to a variety of performance venues. It allows for real-time bi-directional communication between performers and audiences utilising existing 3G, 4G or WiFi networks. Audience members access massMobile through a smartphone-optimised web application utilising common web standards. An offsite server passes data between the audience and the performer(s) and stores the data for later analysis. In this paper, we discuss the goals, design and implementation of the framework, and we describe several projects realised with massMobile.